Drafting machine



Sept. 13, 1932. F. KUHLMANN DEAFTING' MQHINE Filed )lay 2, 1930 2 Sheets-Sheet \1 Aforney I l Patented Sept. 13, 1932 lI'Jmfran s'mxrasl FRANZ KUHLMAIQ'N, `O14" RUSTRINGEN, GERMANY IDRAFTING MACHIN E *Application led May 2, 1939, Seris No. 449,203, and in Germany May 7, 1929.

My invention relates to improvements in drafting machines comprising a head adapted to be moved across the surface of a drawing board and carrying adrafting instrurslment such as a protractor provided with one or two rulers, the said head being mounted on a carrier comprising, for example, two pairs of arm-members pivotally unitedand eachl having the form of a parallelogram. In machines of this class the drafting instrument is mounted on a plate connected with the outer end of one pair'of arms so that it may be turned about a perpendicular axis into diii'erent angular positions, and means are provided for positively locking the drafting' instrument' in definite angular positions, and vin addition means are provided for locking the drafting instrument in any'angular position. My invention relates more particularly 'to the means for positively locking the drafting instrument, and the object of the improvements is to provide lockingv mechanism 'comprising a single lever adapted, lirst,.temporarily to' set said locking means in non-locking position and, second, to set the same in non-locking position and to lock the same in the .said non-locking position. The positive lockingr mechanism comprises a locking member mounted on the 39 rotatable drafting instrument and adapted for engagement with notches formed on the plate or other support connected with the said arm-members. and in my improved machine the said locking member has a two- 5 armed lever rockingly mounted thereon,

which'is adapted when pressing on one arm thereof to be coupled with said locking mem- A ber and temporarily to disengage the same from the' said notches. and when pressing on o the other arm thereof to retract the locking member from said notches and to lock the same in non-locking position.

, Another obiect of the improvements is to provide a locking member which can be accurately adjusted relatively to the notches of the plate for adusting the angular position of the drafting instrument, and with -this object in view my'invention consists in mounting the locking member between a pair of pointed pivot screws, adapted to adjust member,

fcation, and

lhe ocking member circumferentially of the Finally an object of' the improvements is to provide a drafting machine in which the draftinginstrument is 'accurately centred, 55

and withthis object in view my invention consists in mounting the 'drafting instrument on its support through the intermediary of'an anti-friction bearing having one of its raceways formed on two., conical rings 60 pressed together by av spring, so that any wear `of the raceways is automatically compensated. l J For the purpose 'of explaining the invention' several examples embodying thel same 65 have been shown in the accompanying drawings'in which the same reference characters have been used in all the views to indicate corresponding parts.

In said drawmgs Fig. 1 is a plan vie showing the drafting machine as applied to a drawing board,

Fig. 2 is a sectional elevation on. an enlarged scale ,showing the drafting instrument. T5 Fig. 2a is a sectional elevation taken on the line 2li- 2a of Fig. 3,

Fig. 3 is a top plan view of Fig. 2 partly in section,

rFig. 4 is a sectional elevation similar to 80 the one illustrated in Fig. 2 and showing the locking member in non-locking position,

Fig. 5 is a detail view showing the locking Fig. 6 is an rightinFig. 5, p Fig. 7 is a sectional elevation similar to the one illustrated in Fig. 2 showing a modi- Fig. 8 is a top planview of Fig. 7.

In-Fig. 1 I have shown a drafting machine comprising two pairs of arm-members 38 and 39 pivotally united and each having the form of a parallelogram. ButI'wish it to be understood that my invention is not limited to 95 the form of the drafting .machine shown herein. The outer ends of the arm-members 38 are-jointed at 36 to a platel having a central post 2 fixed therein. On the said post two cones 3 and4 are axially shiftable,

elevation! as seen from` the which provide the inner raceway of an antiand into engagement with the shoulder 24', friction'. bearing, and -which are forced tothus retracting the arm 18 out of the notch 'wards each other by a coiledspring 5 laced 19 engaged thereby, and he turns the knob between the uppercone 4 and a isk 6r 11 and the disks 9 and-10 into the desired 5 threaded on the post 2. The outer raceway position, whereupon he releases the lever 26 of the Said bearingxiein the form of a ring permitting the member 16 to be rocked by the 8 formed internally with an annular groove spring 20 wi h the arm 18 into the notch 19 receiving the balls 7 oi the bearing. The ring corresponding to the desired position. Thus 8 is a forced lit in concentric bores of disks the rulers can be set at definite angles of 0,

10 9 and 10 thus rigidly connecting the said 15, 30 etc. If itis desired t0 Set the rulers disks. The disk 9 is formed with perpendicat intermediate angles, say 37 or 601/2, the

ula'r arms 13 and 14 having rulers d fixed draftsman presses with his thumby on the thereto, and the disk 10 is provided with downwardly directed arm 29. Now the cam scale marks 34 cooperating with a mark 33 face 31 rides on the nose 32 so that the lock- 16 made on the plate 1, the said peri-,s providing member .16 is rocked and the arm 18 1s ing a protractor asis known in the art, To retracted from the notch 19. Finally the the disk 10a knob 11 is fixed, which is formed shoulder 30 engages the. nose 32,l whereupon with acavity 12. f

The plate 1 is formed circumferentially held 1n non-locking positlon. Now the 2 with notches 19 cooperating with e, looking draitsman can set the rulers 1n any `angular member 16 mounted on a shaft 17 carried by a position by turning the knob 11, whereupon bracket comprising two upwardly directed the disks 9 and 10-are fixed in position by vthe lever 261s arrested and the arm 16 1s arms lixed to the disk 9 by a pair of serews means of the clamping device 65. If it is de- 48, the disk lobeing formed with e recess 49 sired to set the rulers into another position accommodating the bracket 15. The looking having a notch 19 corresponding thereto, the member 16 is formed. with e downwardly clamping device is first released. The draftsdirected arm 18 adapted for engagement with man grips the knob 11 and engages the upthe notches 19, a. sp1-ing 20 fixed to en eye 21 wardly directed arm 28 with his thumb thus of the locking member 16 and te an upright retracting the shoulder 30 from the nose 32, 3 23 rising from the `disk 10 tending te held whereupon the lmobnis turned and locked in the arm l18 in engagement with the notches position in the manner described above-- 19.y To a part 24` of the locking membel` 16' In the modification shown in Figs. 7 and 8 a pivot bolt 25 is fixed and on the said pivot the Plate 1 iS Inad integral With conical bolt a lever 26 is rockingly mounted which pOSt 35 having the disks 9 and 10 mOnllted .35' is formed an upper arm and lower thereon, Said. dlSkS being together arm 29 both shaped according to the form by a Spring 51 and a nut 52 screwing 011 the of the thumb, a spring 27 being embedded in top end 0f the post 35- The locking member sockets 49 and 50 of the lever 26 and the? 56S in the form. 0f n level haVing a' down locking member 16 for forcing the lever 26 Waldly directed al'm 58 adapted for engage with its lower arm outwerd1y The upper m/ent with the notches 19, and it is mounted varm is adapted to engage a, shoulder 24 of between two pivot screws 46 screwing in the the part 24, and the lower arm 29 is formed ,upwardly directed arms of the bracket 15 and with a cam face 31 and a, Shoulder 3() C0-' fixed in position by means of nuts 42 and 43.

operating with anose 32 formed on one of the ABy screwing the said screws inwardly and 5 arms of the bracket 15. outwardly the position of'the arm 56 rela- The device lfor clamping the rulers in any .tvfly t0 the notches 19 may be adjusted fol' angular positionV com rises a, clamping plate adJusting the rulers relatively to the? scali.. '.65 bearing on the bottom -faees of the plate 1v marks 33, 34. .On the lever 56 a lever 60 isv 5 and the arm 13 and held in position by means lOCkIlgly mounted which is formed with two of a pin 66. To the plate 65 is xed a pin arms 6l and 62 adapted t0 be engaged by the 67 passed upwardly throughs, hole made in thumb of the draftsman, and the downwardthe arm 13 and having a wingr nut 68 screwed ly directedv arm 61 iS Provided With n rounded to its top end, a washer 69 being interposed shoulder 44 adapted to engage a pin 45 iixed between the said nut and the arm 13. i Thus to the bracket 15. Otherwise the construction by turning the wing nut 68 the plate-65 may and V.operation is the same as has been debe thrown into and out of clamping engage- Y scribed with reference toFigs. 1 to'6.

ment with the plate 1 and the arm 13.. AI claim: l

Normally the disk 9 and the rulers carried 1. A drafting mac e, comprising a.v calthereby are held in a certain angular position rier adapted to be moved across the surface relatively to the plate 1 by the locking mem- 0f the paper, a Illemlwl'V rOatably IIlOnntd ber 16 engaging in one of the notches 19, and on said carrier -and carrying a'drafting inif it is desired to setthe rulers in another anstrument, means for locking said member guiar position the draftsman grips the knob relatively to said carrier comprising. locks 11 with his left hand and presses the upper ing member mounted on said rotatable mem arm of the lever 28 with the thumb inwardly ber l and I adapted for locking engagemen with said carrier, a two-armed lever mounted on said locking member and adapted to be coupled therewith when acting on one of its arms to move the same into non-lockingY position and means on said lever operative when acting on the other arm thereof for moving and locking said locking member member and adapted for locking engage mentwith said carrier, a two-armed lever carried by said locking member and adapted to be coupled therewith when acting on one of Vits arms to move the same into non-locking position. said -lever and locking member being provided with corresponding cam faces and shoulders adapted when acting on the other arm of said lever, first to set said locking member into non-locking posi tion and locking posltion.

3. A drafting machine, comprising va carrier adapted to be moved across the surface of the lpaper, amember vrotatably mounted on said carrier-and carrying a drafting instrument, means for locking said member relatively'to said carrier comprising a locking member mounted on said rotatable mem.- ber and adapted for locking engagement with said carrier, a two-armed lever carried by said locking member and adapted to be coupled therewith' when acting on one of its arms to move the same into non-locking position, and means on said lever o erative when actingI on the other arm thereof for movin'g and locking said locking member 1n non-lockingl position, said shoulders being located so that they are thrown out of engagement `with each other when acting on the first-named arm of said lever.

4. A drafting machine. comprisng'a earrier adapted to be moved across the surface of the paper, a member rotatably mounted on said Ycarrier and carrying a drafting instrument, means for locking said member relatively to said carrier comprising` a lock# ing member mounted on said rotatable member adapted for locking engagement with said carrier, Ia two-armed lever carried by said locking member and adapted to be-coupled therewith when acting on one of its arms to move the same into non-locking position, anda bolt carried by said member, there being a cam face and undercut shoulder formed on said lever in position for cooperation withl said bolt and adapted when acting on the other arm of said lever first to. move said locking member out of locking position and-thereafter to lock said locking member in' non-locking position.

IIn testimony whereof I hereunto aiiix my signature. Signed at Bremen, Germany, April 15th, A. D. 1930. v FRANZ KUHLMANN.-

thereafter to lock the same in non- 

